Wheeled mobile robots are popular because of relatively low mechanical complexity and energy consumption. The need of personal mobility supporting personal movement for the aging society is increasing. As mobility needs limited independent power sources, energy management is the key factor to complete tasks. This paper presents a wheeled device with a redundant drive system to continue its motion safely when one of the motors breaks down for some causes. Simulation results show that the proposed method is effective in saving energy approximately by 33 % compared to a conventional one.